A 25kg rock falls for 1.7 seconds. how many meters tall was the building

Which radioisotope is used in dating geological formations?

The brightest star in the night sky in the northern hemisphere is sirius. its distance from earth is estimated to be 8.7 light years. a light year is the distance light travels in one year. light travels at a speed of 3.00 × 108 m/s. calculate the distance from earth to sirius in miles. (1 mi = 5280 ft) g

It is advised not to hold the thermometer by the bulb while reading it